From 1949 to 1979, thirty years in the life of captain Jacques-Yves Cousteau, the famous researcher, scientist, inventor, filmmaker whose greatest achievement is to have made the general public more curious - and accordingly closer - to the sea. A genius, a leader of men and a charismatic opinion maker, Cousteau was not without defects, his being unfaithful to ever-supportive wife Simone for example or else his vainglory..., but let him who is without sin cast the first stone. The spectator leaves Cousteau in mid-1979 at the worst time of his life: his favorite son, Philippe, has just died in the crash of a plane he was piloting. The dashing conqueror of the sea has suddenly become a broken old man, tempted to discouragement but his eldest son Jean-Michel is by his side to help him overcome his grief and go on with his mission...